How server traffic is calculated

Bandwidth consumption over the last several years has shifted from a per megabit usage model to a per gigabyte usage model. Bandwidth was traditionally measured in line speed access that included the ability to purchase needed megabits at a given monthly cost. As the shared hosting model developed, the trend towards gigabyte or total bytes transferred, replaced the megabit line speed model so dedicated server providers started offering per gigabyte.

Bandwidth refers to the data transfer rate or the amount of data that can be carried from one point to another in a given time period (usually a second) and is often represented in bits (of data) per second (bit/s). For example, visitors to your server, web site, or applications utilize bandwidth as the traffic moves from your server to the Internet and vice versa. Connectivity refers to the “access providers” that supply bandwidth, or data transfer rate, through various connection points across a network or footprint to one or multiple data centers where dedicated servers are housed.

Bandwidth measurements are defined (per telecom standards) as the following:

• First – 95th (measured using average bits and speed of transfer)
• Second – Unmetered (measured in speed or bits)
• Third – Total Transfer (measured in bytes transferred)

95th Method: Line Speed, billed on the 95th percentile, average or peak usage, refers to the speed in which data flows from the server or device. The measurement can be compared to mph (Miles Per Hour), or how fast something travels. Line Speed is measured using bits per second, kilobits per second, megabits per second, and gigabits per second.

Unmetered Method: The second bandwidth measurement is Unmetered service where providers cap or control the “top line” speed for a server. Top line speed in unmetered bandwidth is the total Mbit/s allocated to the server and configured on the switch level. For example, if you purchase 10 Mbit/s unmetered bandwidth, the top line speed would be 10 Mbit/s. 10 Mbit/s would result in the provider controlling the speed transfers take place while providing the ability for the dedicated server owner to not be charged with bandwidth overages. Unmetered bandwidth services usually incur an additional charge.

Total Transfer Method: Some providers will calculate the Total Transfer, the measurement of actual data leaving and arriving, measured in bytes. Measurement between providers varies and includes one of the following equations:

• Method 1: IN TRAFFIC + OUT TRAFFIC = TOTAL TRANSFER
• Method 2: IN TRAFFIC = TOTAL TRANSFER
• Method 3: OUT TRAFFIC = TOTAL TRANSFER

One of the reasons people choose to outsource dedicated servers is the availability of high powered networks from multiple providers. As dedicated server providers utilize massive amounts of bandwidth, they are able to secure lower volume based pricing to include a multi-provider blend of bandwidth. To achieve the same type of network without a multi-provider blend of bandwidth, a large investment in core routers, long term contracts, and expensive monthly bills would need to be in place. The expenses needed to develop a network without a multi-provider blend of bandwidth does not make sense economically for hosting providers.

Posted on: 21/07/2009